Ex Parte Sueoka

Patent Trial and Appeal Board

Mar 30, 2016

13561460 (P.T.A.B. Mar. 30, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/561,460 07/30/2012
48915 7590 04/01/2016
CANTOR COLBURN LLP-IBM YORKTOWN
20 Church Street
22nd Floor
Hartford, CT 06103
FIRST NAMED INVENTOR
Kuniaki Sueoka
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
JP920110020US2 6083
EXAMINER
YOON, KEVIN E
ART UNIT PAPER NUMBER
1735
NOTIFICATION DATE DELIVERY MODE
04/01/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
usptopatentmail@cantorcolbum.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KUNIAKI SUEOKA
Appeal2014-004751 1
Application 13/561,460
Technology Center 1700
Before GEORGE C. BEST, MICHELLE N. ANKENBRAND, and
JULIA HEANEY, Administrative Patent Judges.
ANKENBRAND, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner's
rejection of claims 1---6. We have jurisdiction under 35 U.S.C. § 6(b ).
1 Although Appellant states that "[t]here are no related appeals ... known at
this time to the Appellant[] ... that will directly affect, or be directly
affected by, or have a bearing upon the Board's Decision in this appeal,"
App. Br. 2, we note that that the claims on appeal in Appeal No. 2014-
006117 (Application 13/423,552, assigned to the same real party in interest)
recite the same pyrolytic graphite sheet as the high thermal conductive
material of a tool head for bonding silicon chips, with the same thickness
range, as the claims in this Appeal. We also note that the Appeal Brief in
that proceeding raises the same substantive issues presented in this Appeal.
2 Appellant identifies International Business Machines Corporation as the
real party in interest. Id. at 1.
Appeal2014-004751
Application 13/561,460
We affirm.
The Invention
Appellant's invention relates to methods for testing the electrical
connection between a silicon chip and a substrate after bonding and certain
characteristics of the bonding tool. Spec. i-fi-1 8, 4 7. Claim 1, the sole
independent claim, is representative of the claims on appeal, and is
reproduced below from the Claims Appendix to the Appeal Brief:
1. A method, comprising:
testing a state of electrical connection between a silicon chip
and a substrate after bonding with a bonding tool, the testing
compnsrng:
setting a wiring pattern in advance; and
performing a test of checking conduction in the wiring pattern
set in advance;
wherein the bonding tool comprises a tool head configured for
bonding to establish l 00 or more electrical and mechanical ._,
connections between the silicon chip having a thickness of
about 50 microns (~un) or smaller and the substrate, wherein
100 or more solder bumps set on a plurality of contacts on the
silicon chip or a plurality of contacts on the substrate are rnelted
by heating bet\veen the plurality of contacts of the silicon chip
and the substrate, and wherein the melted solder bumps are
solidified by cooling using forced convection of air flowing
frmn around the silicon chip, a pyrolytic graphite sheet
configured to be used in direct contact with the silicon chip, and
having a thickness between about 75 ~1m and 125 ~un; and
a stage on which objects to be bonded together is to be set and
supported, wherein the tool head applies a heat and a pressure
to the objects set on the stage while being in contact with the
objects, and cools the objects mainly by using forced
convection of air flmving from around a silicon chip.
App. Br. 14 (Claims App'x).
2
Appeal2014-004751
Application 13/561,460
Morita
Parrish
Hiramatsu
The References
us 5,667,129
US 6,550,665 Bl
US 2006/0196914 Al
Sept. 16, 1997
Apr. 22, 2003
Sept. 7, 2006
Silicone Adhesives & Sealants - Dow Coming, available at
http://www.dowcoming.com/content/iam/iamsealants (Nov. 5, 2010)
("Silicone Adhesives").
Pyrolytic Graphic Sheet (PGS) Heat Sinking Material - Panasonic,
available at http://www.panasonic.com/industrial/ electronic-
components/protection/heat-sinking-material.aspx (Feb. 3, 2010) ("Heat
Sinking Material").
The Rejections
1. Claims 1, 2, 4, and 6 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Applicant Admitted Prior Art
("AAPA"), Hiramatsu, Morita, and Heat Sinking Material;
2. Claim 3 is rejected under 35 U.S.C. § 103(a) as unpatentable over
the combination of AAP A, Hiramatsu, ivforita, Heat Sinking iviaterial, and
Silicone Adhesives; and
3. Claim 5 is rejected under 35 U.S.C. § 103(a) as unpatentable over
the combination of AAP A, Hiramatsu, Morita, Heat Sinking Material, and
Parrish.
OPINION
After having considered each of Appellant's contentions and the
evidence presented in this Appeal, we determine that Appellant has not
identified reversible error in the Examiner's rejections of claims 1---6 under
35 U.S.C. § 103. Thus, we affirm these rejections for the reasons expressed
in the Final Action, Answer, and below.
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Appeal2014-004751
Application 13/561,460
Rejection j
Appellant argues the claims as a group, relying only on limitations
recited in independent claim 1. Thus, we limit our discussion to claim 1.
Claims 2, 4, and 6 stand or fall with claim 1. See 37 C.F.R. § 41.37(c)(l)(iv)
(2013).
As is relevant to the issues on appeal, the Examiner finds that the
combination of AAP A, Hiramatsu, and Morita discloses all of the limitations
of claim 1, except for a bonding tool having a pyrolytic graphite sheet
("PGS") configured to be used in direct contact with the silicon chip, and
having a thickness between about 75 µm and 125 µm. Final Act. 2--4.
Regarding this deficiency, the Examiner relies on Heat Sinking Material. Id.
at 4. In particular, the Examiner finds that Heat Sinking Material discloses
that a PGS has excellent thermal conductivity. Id. The Examiner concludes
that it would have been obvious to modify the combination of AAPA,
Hiramatsu, and Morita in view of Heat Sinking Material to use a PGS, given
its excellent thermal conductivity. Id. The Examiner further finds that such
a modification would have been within the ordinary skill of the art because it
is "simple substitution of one known element (a [PGS]) for another (AlN
[aluminum nitride]) to obtain predictable results." Id. (citing MPEP § 2143).
Regarding the thickness range recited in claim 1, the Examiner finds
that thickness is a result effective variable because the amount of heat passed
by the PGS (or any layer material) in unit time depends on its thickness. Id.;
see Ans. 9. Thus, the Examiner concludes that it would have been obvious
to modify the combination of AAP A, Hiramatsu, Morita, and Heat Sinking
material to optimize the PGS thickness. Final Act. 4--5.
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Appeal2014-004751
Application 13/561,460
Appellant argues that the Examiner's rejection should be reversed
because "PGS is not merely a simple substitution of an equivalent element to
obtain predic[t]able results." App. Br. 9. More specifically, Appellant
contends that AlN is used on bonding tool heads because it has an excellent
heat dissipation property and a coefficient of thermal expansion ("CTE")
matching that of the silicon used for the chip. Id. at 10. Appellant further
contends that "the greater the mismatch between the CTE of different layers,
the greater the mechanical stress generated therebetween under elevated
thermal conditions, such as during bonding" and that a skilled artisan,
therefore, would have used a tool head material having good thermal
conductivity properties, as well as "having a CTE that is very close to that of
silicon." Id. According to Appellant, the CTE of the PGS is a mismatch
with respect to silicon, unlike the conventional AlN tool head material. Id.
Thus, argues Appellant, PGS is not an equivalent material to AlN with
respect to CTE. Id.
We are not persuaded by Appellant's arguments because they are not
supported by sufficient evidence. That is, as the Examiner finds, Appellant
does not identify objective evidence of record to support the argument that a
CTE match (or mismatch) would have been important to a person of
ordinary skill in the art seeking to address non-uniform bonding heat
temperature between the peripheral and center portions of the silicon chip.
See Ans. 9. Appellant's mere attorney argument on this point cannot take
the place of evidence. See In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir.
1984).
Moreover, Appellant's Specification indicates that AlN was not the
only high thermal conductive material known in the art for bonding
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Appeal2014-004751
Application 13/561,460
applications, and that existing methods of chip mounting included graphite
and other high thermal conductive films. Spec. i-f 7. And Appellant admits
that PGS was "a known material with respect to high thermal conductivity."
App. Br. 11. Accordingly, we agree with the Examiner that it would have
been obvious to substitute the high thermal conductivity PGS for the high
thermal conductivity AlN with a reasonable expectation of achieving a
predictable result, i.e., a high thermal conductivity layer on the bonding tool.
KSR Int'! Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) ("when a patent
claims a structure already known in the prior art that is altered by the mere
substitution of one element for another known in the field, the combination
must do more than yield a predictable result.").
Appellant argues that utilizing PGS as the heat transfer layer provides
an additional advantage over AlN: its conformability allows for minimizing
mechanical stress between the tool head and the silicon chip. Id. We are not
persuaded.
The fact that Appellant may have recognized another property which
would flow naturally from following the prior art suggestions cannot be the
basis for patentability when the differences, if any, otherwise would have
been obvious. Ex parte Obiaya, 227 USPQ 58, 60 (BP AI 1985). Here,
reduced mechanical stress between the tool head and the silicon chip would
have flowed naturally from following the suggestion of using Heat Sinking
Material's PGS as the heat transfer layer of the tool head. Indeed, like
Appellant's Specification, Heat Sinking Material describes PGS as "a ...
sheet with high thermal conductivity and the ability to flex." Heat Sinking
Material 1; Spec. i-f 49.
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Appeal2014-004751
Application 13/561,460
Appellant argues that the PGS thickness range recited in claim 1
would not have been an obvious matter of design choice to achieve an
optimum bonding condition that accounts for both the high thermal
conductivity and minimization of mechanical stress. App. Br. 11. We are
not persuaded by Appellant's argument.
The Examiner finds, and Appellant does not dispute, that "the thermal
conductivity of a layer material and the thickness of the layer determine the
heat transfer of the layer" as indicated by the heat transfer equation. Ans. 9.
Nor does Appellant dispute the Examiner's finding that a skilled artisan
would have been motivated to adjust the thickness of the PGS in order to
control heat transfer during bonding. Id. These undisputed findings are
sufficient to demonstrate that one of ordinary skill in the art would have
recognized layer thickness as a result-effective variable. Thus, we find no
error in the Examiner's analysis. In re Boesch, 617 F.2d 272, 276 (CCPA
1980) ("[D]iscovery of an optimum value of a result effective variable in a
known process is ordinarily within the skill of the art.").
In any event, we note that Appellant's Specification recognizes the
PGS disclosed in Heat Sinking Material has a thickness of 50 µm to 150 µm.
See Spec. i-fi-159, 62 (utilizing Heat Sinking Material's PGS, which has a
thickness of0.10 ± 0.05 mm (50 µm to 150 µm)). This range overlaps
Appellant's recited thickness range of between about 75 µm and 125 µm
and, therefore, renders it prima facie obvious. In re Peterson, 315 F .3d
1325, 1329-30 (Fed. Cir. 2003) ("In cases involving overlapping ranges, we
and our predecessor court have consistently held that even a slight overlap in
ranges establishes a prim a facie case of obviousness."). Accordingly, the
burden shifts to Appellant to show that the particular claimed range is
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Appeal2014-004751
Application 13/561,460
critical, e.g., achieves unexpected results relative to the prior art range. Id. at
1330. Appellant makes no showing in this regard and, therefore, fails to
carry the burden.
Appellant claims to have first discovered that "a temperature decrease
originating from the peripheral portions of the silicon chip causes
solidification of the solder bumps beginning and advancing from the
peripheral portion of the silicon chip." App. Br. 12 (emphasis omitted)
(citing In re Sponnoble, 405 F.2d 578 (CCPA 1969) and Spec. i-fi-140-44).
Appellant argues that this discovery led to the solution of using PGS for its
excellent thermal coupling with a silicon chip without regard to the CTE
mismatch. Id.
We recognize that "a patentable invention may lie in the discovery of
the source of a problem." Sponnoble, 405 F.2d at 585. In this case,
however, the evidence of record does not establish that Appellant discovered
the source of the problem purportedly solved by claim 1. That is, the record
fails to establish that the source of the problem was unknown in the art until
allegedly discovered by Appellant. Appellant provides statements of
counsel, but fails to provide evidence that others did not recognize the
problem Appellant sought to address.
In any event, the question of patentability ultimately turns on whether
the solution to the problem would have been obvious over the applied art. In
re Wiseman, 596 F .2d 1019, 1023 (CCP A 1979). As explained above, the
Examiner establishes on this record that utilizing the high thermal
conductive PGS as the heat transferring layer of the bonding tool (i.e.,
Appellant's specified solution) would have been obvious over AAPA and
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Appeal2014-004751
Application 13/561,460
Heat Sinking ivfaterials. Accordingly, we affirm the rejection of claims 1, 2,
4, and 6 under 35 U.S.C. § 103(a).
Re} ections 2 and 3
Appellant does not appeal the Examiner's§ 103 rejections of claims 3
and 5. See App. Br. 6 (identifying the rejection of claims 1, 2, 4, and 6 as
the only ground of rejection to be reviewed on appeal). Accordingly, we
summarily affirm these rejections. See Hyatt v. Dudas, 551F.3d1307, 1314
(Fed. Cir. 2008) (explaining that summary affirmance without consideration
of the substantive merits is appropriate where an appellant fails to contest a
ground of rejection).
DECISION/ORDER
The Examiner's rejections of claims 1---6 under 35 U.S.C. § 103(a) are
affirmed.
}~o time period for tal(ing any subsequent action in connection vvith
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
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